Yup, you can do this - BGP gives you the flexability to do most things (including shoot yourself in the foot).
If the ISP sends you a full table in both places you have many knobs you can use to tune your outgoing traffic. You can ask that they send you meds, you can use route-maps to set local-pref based upon various attributes (customer routes up one circuit, various ranges, path lenght, etc, etc.). As for incomming traffic, because you connect to a single ISP they should let you break up your announcment in any way you want - after all, you are paying them - so you could announce your entire network through both circuits (for failover) and more specifics tagged with community "no-export". This will keep the more specifics local to your ISP and not polute everyone elses tables. You could also see if your ISP will accept MEDs from you which MAY be a bit easier.
You could also ask your ISP for a bit of help configuring this, after all, you are their customer.
There is a great book by John Stewart called BGPv4. It is really short, easy to read, etc.
http://www.amazon.com/exec/obidos/tg/detail/-/0201379511/qid=1115931074/sr=8-1/ref=sr_8_xs_ap_i1_xgl14/104-9154441-9947947?v=glance&s=books&n=507846
I highly recommend getting and reading this, shouldn't take more than a few hours to read and will give you enough information to configure BGP in a way that works for you.
