Your least expensive option is probably to just buy one of the cheap $20 wall units available at the electronic/battery stores that will charge the 6v SLA battery, then buy two 4 pin XLR connectors and solder those on. Then when you find the wall unit, buy another 4 pin XLR and solder that onto the wall wart. Worst case, you end up with an extra wall unit that can provide you recharge capabilities should you need it.
Wayne