I have not heard of anybody actually using beehive springs on a B20 although their use has been discussed here before. Which ones are you contemplating using? The Chevy LS1 springs are too long. Some Ford v-8 beehive springs may be usable. Not sure about retainers availability.

I have discussed using LS-1 beehive springs with longer than stock valves and push rods along with raising the rocker shaft but that's a lot expensive custom parts. This will also heed a taller valve cover or a spacer between the stock cover and the head.

Isky sells some perfectly reasonable valve springs and retainers and this is probably the lest expensive and simplest route. You will need to enlarge the spring seats a little.

Consider stronger push rods too along with your heavier springs.

I use cheapo Elring head gaskets on my race cars without any issues but I do use cylinder head studs.