Some very good friends of ours just opened up a place in Plano for weddings, banquets, receptions, etc. It is called The Summit Ballrooms in Plano on Summit,
http://www.summitballrooms.com/
The Summit Ballrooms
2553 Summit Ave
Plano, Tx 75074
972-234-1700
The other place I would recommend is called Pickle Hill. It is located out on a farm/ranch North of Plano. The building is "rustic" and they do have two bedrooms upstairs that you can stay in. The outside area is nice if the weather permits and the kids can run around outside.
Pickle Hill
(972) 547-0335
6374 County Road 161
McKinney, TX 75071
If either of these are not "it" there is always Southfork Ranch, Pecan Hollow Golf Course clubhouse and other area clubhouses.
Congrats