CPR Overflow - Drill-free suggestions for my 44g cube?

[andsoitgoes]

Hi all,

I'm in prep to add an above tank refugium, but I'm heming and hawing about what I really want to do here. It makes more sense for my setup to have a sump, but I do not want to drill my main tank. It's just too much headache and risk if I could get an overflow (used, of course) for a reasonable price.

What experience does everyone have with the HOB type, and what might I be looking at cost? Obviously keeping it a reasonable amount is important, but I do want something to make this convenient and optimal for my setup.

Thanks in advance!