Assistance in selecting iron for the VPN network

Depends on your budget.
Little money — D-link and Tplink'and shops, the server with *nix on warehouse (office). But be prepared for failures and disconnections.
Money a little more get the Asus/LinkSys c custom firmware and the same server.
Money — "how much" in each store server on an Intel Atom nettop or anything. Each to supply the most familiar *nix + VPN client.

almost any router with VPN support.
though dlink, linksys, though — it all depends on Your financial capabilities and the availability of a particular model.
Narrow question, otherwise it is not clear what to answer.
What is VPN connection will be used, etc.

Want production? — take the mikrotik.
For a corporate network to take honorory — kink.
\r
PC — for your purpose too.
Total — mikrotik routerboard.

cisco asa sauzaie, is very much where met in the posted shops.

Not simply whether the provider rent channel order, and the head office is to watch, what to put. Depends on the nuances.