Hi Neha,
If you go for BUTADRSEARCH, you can include your own field if it's one-to-one to BP or address number. See my post http://scn.sap.com/message/14561007 for more details.
Later you just need to build database indices for your queries. You can also consider keeping the objects in the separate database buffer pool, if you DB supports this.
Regards, Dmitry