Assuming no weapon skills involved:
Maat's Cap would be the ideal head piece for both TA and SATA (7STR > 1AGI).
Atheling Mantle would be the best back piece for both SA and TA. The attack on it is so massive it over powers the DEX and AGI on the other pieces.
Crudelis Belt would also be your best bet at a waist piece for TA the -8 Att bumps the Sveltesse Gouriz to one of the worst belts you can use >.> it is a really nice evasion belt though.
Tumbler Trunks are the best leg piece for SA bar none.
Rajas Ring will edge out Thundersoul ring in one of your slots for SA by a very small margin.
Shamaya Made a thread on live journal involving sneak and trick gear here: http://shamayaasura.livejournal.com/7505.html
It's pretty interesting, most people do not agree with his stance on movement speed gear but it is obvious that haste is a factor when using SA and TA. Here is a list from that post with new gear added using the point values he described (there may be a few mistakes but someone can check the math if they feel like its off):
SA
(head)
Aias Bonnet (30.24) > Maat's Cap (26.46) > Skadi's Visor (25.41) > Assasin's Bonnet +1 (15.48) = Deceit Mask (15.48) > Voyager Sallet (13.92) > Gnadbhod's Helm (13.84) > Walahra Turban (13.25) > Assasins Bonnet (12.9) > Emp.Pin (7.74) > Heca+1 (0.84)
(neck)
Love Torque (20.04) > Kubira Bead Necklace (15.08) > Spike Necklace (11.34)
(ears)
Suppanomimi (10.8 ) > Jupiter's Pearl (10.32) > Aesir Ear Pendant (8.33) > Pixie (7.74) > Merman's (7.14) > Coral (5.95) > Hollow/Adroit (5.16) > Brutal (5.0)
(body)
Dragon Harness+1 (32.34) Loki's Kaftan (28.38 +5% =??) > DH nq (27.38) > Skadi (26.59) > Anatares Harness (20.64) > BlueCote +1 (16.32) > WarAketon +1 (12.9) > Rapp (10.6)
(hand)
Raider's Armlets +2 (49.28 +15%SA) > Raider's Armlets +1 (34.58 + 15%SA) >ANNM Dragon Mitts (20.44) > Ample Gloves (18.9) > Skadi Bazubands (17.9) > Dusk+1(2xMarch) (17.74)* > Enkidu's (15.12) > Tarasque Mitts +1 (14.28 ) => Dusk(2xMarch) (13.9)* > Merman's (8.94) > AF (7.74) Heafoc Mitts (5.28) > Heca +1 (4.02) > Alkyoneus's Bracelets (-2.28)
(rings)
Rajas Ring (18.9) > Thundersoul Ring (18.06) > Zilant Ring (15.48) > 5Dex Ring (12.9) > Strigoi Ring (10.77)
(back)
Atheling Mantle (26.8 ) > Charger's Mantle (23.8 ) > Nifty Mantle (23.61) > Cerberus Mantle +1 (22.65) > Forager's (21.45) > Amemet +1 (20.25) > Cuchulain's (15.12) > Commander's (11.34) > AF2 (10.32)
(waist)
Cuchulain's Belt (27.38) > Ninurta's (23.04) > Warwolf (18.9) > Speed Belt (15.9) > Swordbelt +1 (14.28)
(leg)
Tumbler Trunks (34.32) > Raider's Culottes +2 (27.26) > Matre Bragezenn (25.8 ) >Raider's Culottes +1 (19.8 ) > Enkidu's (18.9) > Dusk (16.66)* > Oily Trousers (12.9) = Dragon +1 (12.9) > Hecatomb Subligar (12.76) > Barbarossa's (12.75) > Hecatomb Subligar +1 (12.44) > Dragon Subligar (10.32)
(feet)
Enkidu's (17.8 ) > Alcd. Leggings +1 (16.07) Lithe Boots (15.48) > Dragon +1 (13.89) > Dragon (10.12) > Dusk Ledelsens (10.06)* > Leaping/bounding boots (7.74)
TA
(head)
Maat's Cap (35.21) > Skadi's Visor (33.02) > Denali Bonnet (31.18) > Bersail Cap (26.8 ) >Deceit Mask (22.44) > Dragon cap +1 (16.75) > WalahraTurban (17.5) > Dragon (13.4) > Emp.Pin (11.22)
(neck)
Artctier's Torque (20.1) > Hope Torque (16.75) > Crocodile Collar (13.4) > Love Torque (9.51) > Kubira Bead Necklace (6.75) > Agile Gorget (6.7) > Justice Torque (6.45) > Tiger Stole (6.3) > Spike Necklace (5.04)
(ears)
Suppanomimi (19.65) > Auster's Pearl (13.4) = Genin (13.4) > Drone (10.05) > Aesir Ear Pendant (8.82) > Merman's (7.56) > Coral (6.3) > Brutal (5.0)
(body)
Denali Jacket (44.84) > Dragon Harness +1 (41.3) > Loki's Kaftan (36.85) > Skadi (36.22) > DH nq (35.04) > Antares Harness (26.8 ) > BlueCote+1(24.76) > Rapp (14.0)
(hand)
AF+1 (?, ~54.77) > Skadi (35.8 ) > Dusk+1(2xMarch) (21.56)* > Dragon+1 (20.53) > Dusk(2xMarch) (16.8 )* > Dragon (15.92) > Heafoc Mitts (15.21) > Tarasque Mitts +1 (15.12)
(rings)
Stormsoul Ring (23.45) > Blobnag Ring (20.1) > 5Agi Ring (16.75) > Rajas (8.4)
(back)
Atheling Mantle (28.2) > Charger's Mantle (25.2) > Cerberus Mantle +1 (24.06) > Forager's (22.77) > Amemet +1 (21.48) > Aisance Mantle+1 (18.7) > Commander's (15.09) > AF2 (14.96)
(waist)
Ninurta Sash (28.56) > Crudelis Belt (23.20) > Speed Belt (21.0) > Grenadier Belt (18.87) > Swordbelt +1 (15.12) > Scouter's (13.4) > Sveltesse Gouriz (13.13) > Ryl. Knight's Belt (10.06) > Vanguard Belt (10.17) > Warwolf Belt (8.4) > Swift Belt (7.7)
(leg)
Ambusher's Hose (33.5) > Dusk+1 (18.9)* > Oily Trousers (18.7) > Dusk (17.64)* > War Brais +1 (16.75) > Barbarossa's (15.66) > WarBrais/AF (13.4) > Heca nq (-13.68) > Hecatomb Subligar +1 (-17.77)
(feet)
Raider's Poulaines +2 (50.25) > Raider's Poulaines +1 (40.2) > Enkidu's (23.26) > Lithe Boots (20.1) > Dragon +1 (18.74) > Dragon (13.74) > Dusk (13.3)* > Leaping/bounding boots (11.22)