4EAT overhaul

I've lost gears 3 and 4, so I need a rebuild or an overhaul. Costs too much for the shop to re and re, so I'm going to do it myself. I can buy a master overhaul kit with frictions and steels and extras, from MakCo or IPT Performance, for between $300 and $500 but before I do, I thought it would be wise to check with more experienced SVX mechanics.
Can you recommend a better source for an overhaul kit?
Any advice is welcome?
Scott