I have also since come across:
toy r us / babies r us at the shopping centre www.stucki-shopping.ch
(cheaper stuff, but wide range of equipment, and assistants didn't speak english)
Nuggi Haus, Aeschenvorstadt 56, 4051, Basel (also does clothes and lovely toys, on the more expensive side, but a good range of equip)
Jager Babyland were able to order in the high chair that I wanted in 2-4 weeks, whereas Nuggie Haus quoted 6-8 weeks.