Need help with component selection

Hello,
I have been collecting parts for my turbo installation, but I am stalled at this point as I don't know what to purchase . I need a waste gate and blow off valve. When I look on eBay I am left unsure and just want to pull the trigger but don't want to waste money.
Have every thing else, turbo is a Holset , have the fuel system, plumbing , J pipe, carburetor, etc.
This will be a blowthru setup running a maximum 10 # boost, (at least until it is sorted)
Any thoughts would be appreciated.
Thanks