>>Your problem is in trying to do 'Catch all queries'. Rather than re-writing this query for you, I suggest you to take a minute to read these blogs to understand the best solution for the problem:
>>Do you use ISNULL(...). Don't, it does not perform - short blog by Denis Gobo
>> Dynamic Search Conditions in T-SQL Version for SQL 2008 (SP1 CU5 and later) - long and comprehensive article by Erland Sommarskog 
>> Catch All Queries - short blog by Gail Shaw
>>Sunday T-SQL tip: How to select data with unknown parameter set Nice blog by Dmitri Korotkevitch
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>I didn't do it that way because I always thought that dynamic queries required a recompile each time and that was bad?

This is not correct. You can re-use the execution plan if you pass parameters into dynamic query properly. All the listed blogs explain in details how exactly you need to dynamically construct the query.