I'm going to skip suggestions on specific areas and instead give you a snapshot of likely conditions and how they might impact your choice of route.
Firstly, you'll be dealing with lots of running water - in the streams and rivers and out of them. So planning a trip that keeps stream crossing to a minimum is a good idea, as the streams/creeks/rivers can be very dangerous to cross when running high.
Walking on snow at that time of year can be great as long as you get going early in the morning while things are firm, and don't plan on covering a lot of ground in the afternoon when the snow is at its softest.
Depending on the elevations you'll be at, I'd suggest being prepared to camp on snow, even though you'll likely be able to find bare spots.
Weather at that time of year can be almost anything. You have a great chance of having pleasantly warm afternoons and bright sun (and bring plenty of sunscreen, the sun on the snow is potent), but you can have rain, snow, anything. So be ready to enjoy whatever the skies bring.
You can keep tabs on the snow depth in the sierra on this site: http://cdec.water.ca.gov/snow/current/snow/
If the area you're looking at has remote sensors close by, you can see the snow water content in real time, and estimate the depth from that. If there aren't sensors close by, there are manual measurements taken at the end of each month. Very handy.
Footwear is a tricky question. You'll be on snow sometimes - mostly pretty wet snow - and on soggy ground often. So keeping the water out is definitely an issue. My trips at that time of year in the sierra are ski trips, at the higher elevations mostly, so I'm in plastic backcountry ski boots, and have little to offer in terms of advice on hiking footwear. I have to hike in my ski boots sometimes, mostly at the start and end of trips to get from trailhead to solid snow or back again, but they aren't what you'd want to hike in if you had a choice.
It's a great time to be out there. You'll have most places all to yourself and the mountains look great at that time of year.
Oh, and navigation without a trail should be something you're good at, as the trails may be covered. Have fun!