Given the minimal hardware requirements of SME, you can run it on a computer you can get for a couple of bucks at a thrift store or get for free in the trash! My home SME server is a Pentium II (yes, II), 233 MHz, with 192 megs of scrounged RAM. True, the hard drive is 100GB, but that came later.
And given that SME isn't useful as a desktop OS, what would you DO with it if it were running on your only computer?
But to actually answer your question, you can try one of the many boot managers out there; here's one that's old but effective and fits neatly in the first track of the HDD. I don't KNOW if it will boot an SME partition; what the heck, give it a try.
http://btmgr.webframe.org/You'll have to set up SME first, then resize its partitions with a partition manager, as SME assumes that it's allowed to take the entire HDD and will wipe out anything that was there first.