You can order a single humbucker, stratpickup and teleneckpickup at BKP.
Slash uses alnico pro-II pickups, but I wouldn't go for an AII-magnet like a Stormy Monday in a pine body/bolt on-telecaster. Too bright imo.
I think you better pick a middier pickup like the Abraxas or the Crawler. They split well and will add beef to your tele, but still retain enough PAF-pedigree. The Crawler in my swampashstrat does classic rock excellent
For the middle I would pick an Irish Tour, that will balance most pleasant with the splitted humbucker. As a standalone pickup it's really good too. For the neckposition I recommend a BG50. With this combo I think you'll have a super versatile tele (but actually a HSS-strat-layout).
You can find wiringdiagrams for HSS in the section 'support'.