Reputable T5 Rebuilt Transmissions?

I'll be replacing my trans in my 89 5.0 LX and I wanted to know if there were any reputable transmission builders I should be going to. I checked out modern driveline and emailed them exactly what was going on with the car and he said I'd be better off give him my core (worth about $100) and just buying a new trans at $1295 (about $90 for shipping). Now I'd like to avoid getting a new trans if I can save 500 or 600 bucks by going with a good rebuilt unit. However, Brothers Performance sells new Ford Racing Tremec World Class Transmissions w/ the input bearing and a short throw shifter for $1295 (free shipping), which I think is a VERY good deal...

I don't have time to rebuild my own with a kit, nor do I think I have the transmission expertise to do it, so I'd rather just get a reputable shop to either rebuild mine, sell me a rebuilt unit, or just buy a brand new one if I should go in that direction. I live in the North East Philadelphia, PA area.

well that's the thing, I'm not sure how bad it is in terms of it being worth rebuilding or not. Like I said, I was told I'd be better off just buying a new trans. That was the only opinion I've gotten, and that was through an email...

My other option is to just exchange my core for an already rebuilt one. I was just wondering if anyone could tell me who a reputable re-manufactured transmission seller is. Whether they would rebuild mine or just take mine as an exchange for an already rebuilt unit.

Okay. Yeah, sorry for not describing. Trans is not whining. In my opinion, and this is coming from an IT person, not someone with an auto technician background, I don't think the trans is in bad enough shape to where it wouldnt be worth rebuilding. It has 105k on it (I bought the car at 78k) and it grinds and/or bangs when putting into first/reverse. You absolutely can't get it into first/reverse without a violent bang or grind without first having the car at a complete stop and without shifting the car into 2nd first. After the car is moving, it will bang into second if you are getting on it and shifting fast through the gears and/or you don't have the clutch to the floor, completely engaged for at least 1 whole second. As for 3rd through 5th, it usually up-shifts and down-shifts perfectly through those, only with the very seldom grind or bang.

There's no whining, no burning, you can't hear anything of an ill-nature going on in the trans other than the grinding and banging when shifting to 1st/reverse and sometimes 2nd. So it's not like the trans is throwing medal or anything.

I told this exact story to the guys at Modern Driveline (which by doing a few searches, it seems to be a reputable shop), and I was surprised to get such a quick response of "just get a new transmission," but I am no transmission expert so I can't make judgements, I can only go with my gut. IMO, if my trans is to far gone for a rebuild, then what trans does qualify for one lol.

Yes, once they crack it open, that's when you know EXACTLY what's going on, so I know I can't expect an exact diagnosis over the phone/email. I'll give these guys a call. Thanks!