I would continue your endeavor with 5.3. As reddazz said, you should have no problem with 5.3
I can tell you I've not had any problem with it booting. (I use my slackware lilo to pass control to
the /dev/hdb MBR -to use linux terminology) then let the FreeBSD bootloader continue as it normally
would. But like I told you in another post, when I'm installing FreeBSD, I disconnect my other
hard drives - just in case - and to make sure the bootloader gets written to the proper MBR.
I'm on my 4th reload of FreeBSD - but it was me who screwed it up (yes, all 3 previous times
Hope your next attempt is a successful one. This one is for me is going well.