store system w 4-8 cameras ?

["- Bobb -" <bobb@xxxxxxxxxxx>]

Have a friend looking to buy a convenience store and would like
info/recommendations on a pc-based system that would have 4/6/8 ?
cameras recording to the PC -  in case of  pettty theft/ hold up etc .

Any online pointers to " the benefits of x cameras  over the
alternatives". for instance, with a DVR system, would it be best to go
with 2- 4 input cards vs 1 8 input card ?  How many fps ? how many
cameras per aisle ? overwrite the aisles every ... 5 minutes , 30
minutes ? How much disk space per minutes etc etc.? I see wireless
systems as an option,  but wouldn't they be subject to jamming by a
prospective robber etc ?

He asked me my opinion since I know computers , but other than the
yellow pages/ google etc I don't know how to research this. Since he
brought it up I realized that I didn't know anything about this and
looking to learn.  A lot of what I read here is over my head and
specific  ( Napco firmware , surguard mrl2 etc). Thanks for pointers/
info as to what he should consider when buying a system.

Bobb