Custem mobles in maps+other

[elfwood]

i am making a warhammer map in Battle for middle earth style.

And i was wondering will it slow the down download(i intend for it to be downloaded over battle net)to much if i added 1 custem modle to it.

also do u like the unit limit in Battle for middle earth and should i remove it)(in Bfme you stop spawning units when u have 180)