If you like the car, and are up for the work/expense - MT swap it. There are swap guides online that go into all the details necessary - it's not that difficult.
$175 Pedal assembly new
$ 90 MT cross-member used
$600 clutch kit & flywheel new
$100 short shifter & knob new
$100 interior boot new & bezel trim used
$100 master & slave cylinders new
$ 45 clutch line new
$300 DSS steel driveshaft new
$1510 + used trans $250 = $1760
I just found everything above on eBay, FRSport and CourtesyParts.com - just need the transmission and maybe a lower trans harness from Wiring Specialties.
Try
http://www.car-part.com, partouts on Zilvia Marketplace or local 240sx Facebook groups for reasonable prices on used parts. You could reduce that total a lot with used flywheel, pedal, shifter, driveshaft etc.
SR swap will run you $3000 plus for sure on the low side. Check out a real list of what all is needed and you will see it adds up quickly. KA clutch kit & flywheel wont work on SR but the rest would - if you go SR later, sell 'em with your KA.
Good luck!