Strange, but finding brand new 1080p 60 hz screens nowadays is surprisingly tricky. On the plus side, if you do get a monitor that is above 60Hz, it should still work on the dock, but ofc the refresh will be capped at 60, similarly with the resolutions. For work purposes, high refresh rates will provide very little benefit (for most office work), whilst increased resolutions provide significant benefits, equivalent to having a bigger desk to fit more paperwork on. Panel types, VA has better contrast ratios and response, IPS has beter colour and viewing angles. Usually VA is more work appropriate, though there's nothing wrong with having an IPS either.
You can get both screens almost within the £100 budget for the one screen, though an extra 40hz that won't cause an issue since the dock will bottleneck you anyway:
You can get a slightly better IPS panel for pretty much the same price (75hz max refresh):
If you go elsewhere, i.e. certain major online retailers, it is possible to find what seems to be the last 2 1080p60 screens for £100 or less. One called AOC-B241H and another is Acer KA240Hbid. Given that one can get better screens for less, it's not worth it IMO, 1080p60 screens seem to be overpriced at the moment, likely due to dwindling supply (and companies knowing that the only significant market for such products these days are businesses, who will usually pay more than regular folks).
Technically, you can fit in a better USB-C dock and better screens for your entire budget of 2 screens. Most decent USB-C docks with multi-monitor support 2x 4k60 and cost around £40. Note that it's possible to find slightly cheaper docks out there, if you were interested.
My basket at OcUK:
Total: £164.98 (includes delivery: £0.00)
With a better dock, looking around there's plenty of high-refresh 1080p screens out there for £100 or less per screen, though as mentioned, it usually provides less benefit for work scenarios. Higher resolution monitors start over the budget at £120ish for 1440p and £140ish for 4k.
If it's for work, I'd just go for the cheapest 1080p VA/IPS option, given that higher refresh is both out of budget and not compatible with the dock.
