Comboboxes with inline checkbox for multiselect 😂

Once I had to style comboboxes with only css so that they would look equal on all browsers... Equal meant they would look like the IE comboboxes with 2 pixel fugly borders, a gray focus state that felt more like a disabled state to me ... And it was horrible!

So, we've finally finished our ASP.NET Webforms application, and we're looking onto MVC. We've decided against core just because it isn't as stable yet, and there are fewer libraries, which I'm cool with. However, we still have some baggage from webforms left in our way of approaching the problems. Since the college at large has a custom bootstrap release, we already have bootstrap and jQuery included in the project. What is the best way of going about implementing an equivalent of ComboBoxes, gridviews with paging, and anything else included in the default asp elements and AJAX toolkit ones? My boss is very much against taking in anything but large, well supported libraries like Angular & Angular-UI, so no jQuery plugins unless super stable and supported. I'm trying to save us from having to buy DevExpress for like 3000 across our team. Sorry for the long bullshit, and thanks if you even read it!

Anyone who managed to use comboboxes with Gtk# on monodevelop? I can't get it to work with both Gtk2 and 3