Hi femme,
Yup, its is indeed that Catholic priests can only do the solemnisation IN church and no 2 ways about that.. Frankly, having a solemnisation in church is truly a one-time experience which i think one will never forget if you chose the right church. FYI, my hubby is a non-catholic who doesn't really fancy the thought of going through a church wedding, but after going through the marriage preparation course and after visiting one particular church in town, he changed his opinion totally about church wedding and was looking forward to it - we are now 1.5yrs married..
I suggest you take some time to look at the different churches and you will find a church which you will want to solemnise in... After all, wedding is the 3rd sacrament under the catholic faith which catholics undergo, therefore being a sacred ceremony, its best to do it in church..
Hope this helps..