remove ISO-UK and move basic alice bars to basekit
As a UK ISO user, I'd prefer you kept the UK ISO keys in the base kit, but if you do take them out then I don't think it's necessary worth replacing them with the Alice bars as this just creates spare keys that are useless to anyone who's not using the set on an Alice board. Also, adding the basic Alice bars to the base kit would reduce sales for the space-bar kit.
If you need to remove keys from the base kit to reduce price a bit then better to strip it back so it supports ANSI, terminal ISO and 40%, then offer additional compatibility through a space-bar kit and NorDeUK set.
I'd still prefer you kept the UK ISO keys in the base, but if you take them out then I don't think replacing them them with the Alice bars is a good exchange as it just favouring one subset of the community (the minority who use Alice) over another subset (the minority who use UK ISO).