I'm building a slim PC around a mini ITX motherboard, which should pack enough CUDA power with a low price. I came into the conclusion that GTX 750 Ti is a good choice (OK performance, low price, low heat generation).
The slimness I plan to achieve using a 90 degree PCI-e riser card (similar to http://www.ebay.com/itm/PCI-Express-16x-Riser-Card-90-degree-Right-angle-4cm-Adapter-Card-2U-/170914230015)
However, the problem is that I don't know if the GPU will fit a specific motherboard with a specific CPU cooler and if the RAM modules will interfere. Is the 750 Ti a reasonable choice and is there a difference between different manufacturers? Or should I look into some slimmer options? I am building a custom case, so PSU and SSD can be placed anywhere, even outside the motherboard's area.