As far as upgrades go, here's what I've done to my 700 SPS in .30-06 :
Badger Ordnance Tactical Bolt Knob installed by GA Precision. This knob is an absolute must have IMO. I live about an hour from GAP and they installed the knob on my bolt while I waited using their CNC machine. The fit/finish is superb and the added grip and extension you get from it is perfect.
http://www.gaprecision.net/boltknob.html
Also, the Williams replacement bottom metal is a good choice. I really like it. It has a better fit and feel.
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=115533
Currently, I'm looking at the Bell and Carlson # 2461 stock. It's a Medalist stock with no checkering. It still has the full length aluminum bedding block. Just as courtesy information, most aftermarket stocks are designed to fit the "magnum barrels". If you have a standard barrel like I do in .30-06 there will be a slightly larger gap between the barrel and the stock. We aren't taking about much though. Magnum barrels measure .960" in diameter and standard barrels are .890" in diameter. You're talking .035" on either side of the barrel. So there really isn't a huge difference.
http://www.bellandcarlson.com/
If you can't adjust the trigger and want a replacement, Jewel, Timney, and Rifle Basix are pretty much standard aftermarket triggers.
Also, you might look into a nice coating. GAP does Cerakote. I'm looking at a Roguard/NP3 combo. Cerakote is $265 and Roguard/NP3 is about $320.
Those are just some of the things that I have done and are planning on doing. Hope that gives you some more ideas!