Lothar Walther, and Shilen would be my two choices hands down for a pre-fit Savage. I have a Pac-Nor on my savage 111 swede and it definitely will be the last Pre-Fit I *EVER* buy from Pac-Nor!! The camber was cut crooked, when I called them telling them that the absolute best I could do was 1 MOA at 100 they basically said "Congrats you are doing good!" I paid big bucks for a super select match barrel and I get that ****!!! F-That !!! On top of that, the 3groove barrel happened to be "A bit on the slow side", and my sisters Savage 10FP with oem barrel on it cleaned up in Half The Time with over twice the rounds down range between cleanings!! Ya know, I have held my silence for years on this damn barrel and Pac-Nor now...but I am not about to let some poor sap get F-ckd like I did and not at least Tell Him About It.
I will say that *AFTER* I had it converted to AI, it suddenly shot bug holes, and continued to shoot them for the better part of 1500 or so rounds. I had over 1k rounds down the tube just trying to break into some real accuracy. Know what? The 140gr Gamke Kings at Exactly 18 thou off the lands on well prep'd Win brass with Wolf Primers and H4831sc was THE one and only load to EVER break below 1MOA, that load printed .2 / .3 with great regularity. Oh, and the bullets were sorted by weight and ogive and Sorta Tipped for conformity. That load was the absolute biggest pain in my ass in over 20 years of reloading! Then I go and roll it up in an AI and that barrel shoots damn near anything in 1/2 inch or less with very little effort.
You may have great and/or awesome luck with Pac-Nor on NON-PRE-FIT barrels, but watch out for their Pre-Fit! This is why I advise Shilen for sure, and LW by what I have heard several times now. If you call Shilen and tell them "Hey I want a Savage Pre-Fit with a Dead-Ass-Square chamber, they will deliver to you just that and if for any reason it is NOT they WILL make it right. Real good CS on Shilen. Is every barrel perfect? Nope! But they are great folks to deal with.
By the way, this is the first time I have broke my silence on the forums on this particular issue. After the re-chamber by .... Afterwards, it shot great and with ease. It still cleaned like ****, but shot great. I have never Wanted To BURN Out a barrel so bad, ever! I am very glad it is basically dead now, and time for a rebarrel on the Savage. But I am waffling bad on what I will choose. Having hell deciding between a 280 Nosler AI and a 25-06 AI. Heh.
Now as for barrel length, over on the hide Dar I think it was cut a 260 back quite a bit and was surprised at how little velocity loss he had. After reading about his experience, I would be tempted to roll with about 22" heavy fluted barrel myself. Give up some velocity, sure, but gain in Handi-ness.
You may find that $700 puts you on a bit of a tight budget. I would keep your stock for now, and stiffen the fore-end, "fill" the butt, and bed it. Now if you get a couple of rods you can finesse them into the fore-end and then fill over them with something like marine tex and you will gain pretty reasonable stiffness. Enough to get you by until you can save up for a Manners or some other of the truly excellent stocks out there. There is another thread here where many stocks were listed, most all of them real good choices.
Bolt Head, you just have to order the bolt Head kit and change it. Do a bit of reading and go for it, it is pretty easy if you are at all mechanically inclined (you are).
Remember to get some Go-No-Go gages when you get your action wrench. Also, you will need some kind of action vise. I was lucky enough a friend machined a block set out of aluminum that I put in a regular vise and clamp down. The barrel change is easy.