Possible learning moment for me and free bump to the OP: What does it matter if the GPUs are mix-matched? Should just be a matter of performance? Or.. was the question just to clarify on the specifics of the product advertised?
1. It doesn't look pretty.
2. Different cards have different quality and grade of parts/chips/etc. Mixing them and running at the same speed can give mixed/strange/full moon type results in rare cases.
3. Why would you do that.
4. Cooling is difficult to regulate with different cards.
Each manufacturers card and model will run at a different set of clock/mem/thread/etc with different stability and heat results. Tuning and re-tuning these rigs would take three times as long.
Most importantly #3.
Don't care about #1, #2 rare cases, #3 he's a repair guy, I wouldn't be surprised if some of these cards are refurb/used which wouldn't bother me but should probably be specified, #4 cooling is always a concern and there are many ways to manage.
for the OP, thx for the service you provide. you said the $90 for just the case/frame is the cost shipped in the USA? Does that include Alaska? If so... damn, wish I would have waited before I embarked on my PVC project. But I'll def keep you in mind perhaps for future projects. Mind me asking where you get your aluminum and interconnects?