truncate in transaction blocks read access

I have a million-row table (two text columns of ~25 characters each plus two integers, one of which is PK) that is replaced every week. Since I'm doing it on a live system, it's run inside a transaction. This is the only time the table is modified; all other access is read-only.

I wanted to use "truncate table" for efficiency, to avoid vacuum and index bloat, etc. But when I do "truncate" inside a transaction, all clients are blocked from read until the entire transaction is complete. If I switch to "delete from ...", it's slower, but other clients can continue to use the old data until the transaction commits.

The only work-around I've thought of is to create a brand new table, populate it and index it, then start a transaction that drops the old table and renames the new one.

Any thoughts?

Thanks,
Craig