For insulation, if you plan to do DIY, you could do the pad route (or even try Reflectix, which I plan do for temps down to 60 this year as something new) or an underquilt made with APEX which is a synthetic insulation.
Apex comes in varying degrees of thickness, the thicker the warmer. I am no expert on CLO values and guesstimating temp ratings...but a UQ with 2.5 oz APEX (sandwiched between 1.1 oz ripstop) may do the trick. If it is too warm you can vent the ends to get some air flow.
If you search the forum (DIY section) for APEX you should be able to find more specific insulation. I went the APEX route as I am not brave enough to deal with down yet...and APEX is less expensive, plus the other perks synthetic insulation provides.
As for top insulation, sounds like a fleece blanket may work...or if nothing else a sleeping bag mostly unzipped until you get an idea of what you may need in terms of ambient temps.
Now if you want to buy...I would recommend Wilderness Logics, he has both UQs and TQs made with down and he is "good people" to deal with. Not to say the other cottage vendors are not, but I have had great experience with him (Marty) and will go back to him first for that reason.