M, the 7-08 of yours will 1/2 MOA easy as it is , I have a 595 the model before (IMHO Tikka/Sako went backwards with the T3), in 7-08 and I have taken lots of game out to 500 with it.
Ive mucked around with various bullets from 115 gr Speer HP-150 gr Serria 150s they have all taken game ranging from Hares through to Red deer with relative ease.
Sadly my 708 is now my bush gun so it dos'ent get out much like it use to, but if I ever just go for a rekie to a new block its the go to gun!
The two loads I have settled on are a 120 gr Nosler BT for light skined stuff(goat culling load really) but my main hunting load is the Nosler 140 Accubond which performs superbly. I shot a 80lb pig on Sunday nite,close really at 178 yrds through the right ham, smashed the hip joint, thru gut cavity broke its neck and stopped just under the skin behind its left ear! most impressed.
If you want another stock for it, Manners are now making composite stocks for the T3s they will be superb stocks but, I would suggest tunning yours as it is with a handload and just shoot it before going down that path.
If you havent yet lighten the trigger too, very easy job, if you google it it should come up with pictures if not PM me and I will send you some but its waaay simple and you cant really go any lighter than 1.5 lbs and its totally safe.
The Optilock rings are fine rings too I had people tell me that they crap because the Hex bolts strips the Hex part easy!! 15 IN/LBS tourque its all that it required, they will never ever strip! Ivce got them on my 375 H&H and in 4 years and 1000s of rounds they have never given me grief so they are strong.
Thats my 2c, you have a made an excellent choice anyway and will give you years of enjoyment.
Damm I got all carried away and didnt answer your question, they dont really need it, for factory guns theyre really good, and theyre made in Finland!!!
I asked a very well respected gunsmith about truing a Tikka action, "havent found one that needed it"
As for bases etc they have screws in the action for them, plenty of them out there! if you for some reason dont like the optilocks.
Limbsaver make recoil pads for them, Ive covered stocks and trigger
Anything else you need to know just ask.