I will add that although you can make whatever your heart desires, don't do something that looks to difficult!
And really don't let them pick it out! I'm still working on a quilt that my friend picked as her wedding quilt and 4 years later I'm still not done it. I let her pick and there is honestly not a single piece in that thing that is over 2 inches wide. I did decide though that it is no longer going to be a queen sized but a lap... it's taken this long to get that many squares done. Now I'm using the rest of the cut peices for a piano key border. I still am a little mad that she handed me back what I originally got her and told me that she didn't want it she only wanted a quilt.