Get one of the repeater cables from seller mre1032 on Ebay. He offers a couple of different versions that will suit your needs well. He's welll known in the Motorola community and highly reliable. In fact, check out some of his other offerings for the 1225 mobibles.
The M1225LS can be modified back to a standard M1225 by simply removing the aftermarket board that makes it a trunking radio. That will give you a 20 to 24 channel conventional radio.
And you won't need the LS version of the programming software. Find version 4.0, it runs just fine under XP. If you are acquiring an older PC for this, get one that has a real serial port. Then get a serial version of the programming cable. It will be much more reliable than trying to use a USB cable on the older PC and software. The serial cable use COM-1 so there's no dicking around with comport assignments. I bought a refurbed Panasonic ToughBook CF-29 with XP installed on Ebay. It is rock solid for the M1225 as well as my newer Professional Series and Commercial Series units.
There is tons of information to be found about the M1225 (and LS) at batboard.batlabs.com, radioreference.com, and repeater-builder.com. You will probably find my posts and questions about this exact subject on the batboard and RR (user name is STeveC0625 over there.) I bought a 1225 not knowing it was an LS model. By searching at RR and the batboard, I found all the answers I needed and then some. I ultimately ended up selling the aftermarket board which reduced my purchase cost of the radio to almost zero.
I dont recall what programming for accessory pins the LS offers but thats the biggest issue you may have. Use good shielded cables between a duplexor and radio.
