Question about radio choice

RouterOS Wireless Networking
1

Hi all.
I plan to give wisp service using Hiperlan.
I studied all routerboards and I understand where use one or another.
I have some question about radios:

  1. R52 is the best choice for a CPE (one user) ? Do you know a better (but with similar price) solution ? (i.e. Winstron NeWeb DCMA-81)
  2. R52 is the best choice also for a base station (40 users) or someone known a better card ?
  3. if I put two radio cards in a rb433, could I have interference problems when both works with heavy load ? Exists some contromeasures (i.e. an insulator between them) ?
  4. for a CPE is better rb411+r52 or directly the 411AR ?
  5. in a base station box (with a rb433) is useless or not to insert a discharger before the ethernet port ? i.e. a lightning could induce a spike in ehernet cable ?

Thanks for any hint you could give me.