How did you determine that the deadlocking was due to FK lookups?
Legitimate FKs should be used when possible. FK definitions in SQL itself are vastly more efficient than any code you write to try to do the same thing yourself.
SQL DBA,SQL Server MVP(07, 08, 09) Prosecutor James Blackburn, in closing argument in the Fatal Vision murders trial:
If in the future, you should cry a tear, cry one for them [the murder victims]. If in the future, you should say a prayer, say one for them. And if in the future, you should light a candle, light one for them.