[Help] HTC Desire ROM


few days ago I've received a HTC Desire as a gift, it was already rooted and some after market rom installed on it, after i did some reading on the forums and other blogs I think I understood what the rooting is all about and custom roms as well. BUT, my problem is, I want to take it back to the stock ROM as I am getting tons of errors and some features not working, or any stable good ROM that people can recommend? it's confusing to start off with a custom ROM as I have no idea what's going on as this is my first Android phone. Please help me I'm really lost in all of this, and I dont want to brick my phone.

Software Information
Firmware version
Baseband version
Kernel version
trip@trip-laptop #6
Build number
1.21.EACR.2 CLxxxxx release-keys
Software number
Eng. Amir Custom ROM r4.3 for the HTC Desire
Browser version
WebKit 3.1