You didn't specify you were looking for an ISO or UK layout.
The Drop CTRL or Alt, (if you wanted to go smaller) are hot-swappable but only available in ANSI/US layout.
As you're likely to need to order the switches (and possibly the key-caps) from overseas, you're still likely to be required to wait a week or two for delivery, so waiting for the board shouldn't make a huge difference to the time you'd need to wait to have a completed board in your hands.
Off the shelf hot-swaps in the UK, I can only see the GMMK Compact Barebones on Amazon but as you pointed out, this is 60% with no dedicated arrow keys.
Other than pointing out you'll need to wait for switches and/or key-caps and might as well look abroad for the board too, I'm afraid I can't really help as "kit" for making keyboards isn't exactly thick on the ground in the UK at the best of times. Building a keyboard from UK-sourced components during lock-down is going to be even harder I'm afraid.
Amazon…there’s one at 64 at the mo
Glorious PC Gaming Race GMMK Compact Keyboard Barebones ISO Layout https://www.amazon.co.uk/dp/B07L32V19W/ref=cm_sw_r_cp_api_glt_fabc_1GX3GNNZ1HQQZ88H1MAB
Does this combo work? I'm very new to mechanical keyboards and would like to start with this build. Thanks in advance!
https://landingpad.shop/products/jwk-alpaca-switch?variant=37883112882350
Do zealios support rgb
Do Zealio v2 65g support rgb backlighting? For example if I bought this https://www.amazon.co.uk/Glorious-PC-Gaming-Race-Barebones/dp/B07L32V19W then placed the switches in would the rgb lighting still shine through?