Planning to make my custom case.

[lumi]

There  is a way of mounting slim DVRW drive together with 3.5 floppy in 5.25 bay. Take a look for example here: http://www.provantage.com/startech-slimcdfdcage~4STR90EK.htm

There is a lot of manufacturers with different specifications and prices that sell such brackets, just use the Google to find the right one.

lumi