Yep they fit, I've ran the MM Selectro hubs on my 70's dodge kingpin in my scrambler back in the day... not sure it was worth it though after breaking them many times I eventually went to drive slugs... and then broke the shafts and dished out more cash for 4340 35spline axles and new drive slugs... sigh...(my only advice is) don't spend money on the inferior parts or an intermediate type setup.... like extreme rock crawling on 30spline axles, use the slugs and get used to having full time 4wd.
with that said, your question was to get some Selectros:
Try to call this guy at winches plus:
http://www.winchesplus.com/ I think they are around $130 a pair, but he may have used ones or new old stock/bits/pieces/parts.
Also try mile marker for shiny new stuff as they are the original manufacturer:
http://milemarker.com/product_type/hub/
Search Part
#11034-01
You can also use your local distributor Four wheel Parts Wholesaler's for the MM part $182 and they might price match a cheaper outlet:
http://www.4wheelparts.com/Drivetra...spx?t_c=12&t_s=237&t_pt=6075&t_pn=MIL11034-01
NOTE:
I too do NOT have selectable lockers in my FJ40, but swear by the drive slugs for price/strength/simplicity.
I actually run aftermarket 35spline ones (internal type that were $185 Shipped), but here is a link to external too:
http://www.pirate4x4.com/forum/axle...-external-drive-flange-kits-30-35-spline.html
those are $220 shipped with discount code: PirateDFE