You have a few options. You can buy aftermarket (Dorman, Pace Setter, etc.) for roughly $300 apiece. That's $600 total, plus gaskets. If you pay someone to install them, it's about 8hrs labor at shop rates. The Pace Setters are known to be junk with tremendous fitment problems and I'd stay away from them. Dormans will likely fit. Now, here's the shakedown. You spend $600 on parts, and whatever labor costs (either you do it yourself or pay the shop rate). In a year or two, you'll very likely be doing it again. And that's another $600 for parts and 8hrs shop labor or a full day of your own time.
Alternately, you can swap up to JBA long-tubes ($450-ish and up pricing) and buy Uprev ($500 or so, I think). You won't be back in there again for exhaust manifolds, and you will have more power, more torque, and possibly better mpg, if you're lucky and can keep your foot out of it. You can do it without the b-pipes for now, and it will work. Or you can swap up the whole thing, and be done with it until you sell your truck or the wheels fall off.
I know which way I'd go. Headers and Uprev and saving for b-pipes at least. You're talking $200-300 difference in initial cost for headers/Uprev, and never having to do the job again, versus saving the $200-300 now but spending 2-3x that in short order to re-fix the problem. I know $200-300 is a lot of cash. But scrimp on some stuff and save it up. You'll be glad you did.