You also can buy Climashield in two types from
Insulation is listed under "Fabrics".
Climashield Combat in
2.0 ounce a sq yard at $8.95
3.5 ounce a sq yard at $10.95
Climashield XP in:
2.5 ounce a sq yard at $9.95
5.0 ounce a sq yard at $13.95
There is very little difference in the insulation between these two types. The differenc is the weight per sq yard. You have a few different options if you are trying to build to a certain total weight.
All things being equal I will take Combat over XP.