Tanx Rudy
very inlighting !
to awser: It pppoe will have a maximum of 30 clients max speed up 200kb/s down 300kb/s with the use of a windows dialer program ( no cpe's ) this because there is no internet at the moment and telefonica wont place lines for only 30 users! (let me revrase they will but everyone will have to pay approx 1500,- euro) and all owners don't want to pay to mutch and just want simple internet for mail msn and browsing.
speed availeble: for as yet unknown (but as seeing there is only adsl availeble on lanzarote im thinking a max of 10Mb/s down)
for the Band I was thinking about using 802.11G
For hotspot users (temp. users mostly checking mail,facebook, twitter) I was thinking up 128kb and down 256kb using hotspot and usermanager.
then yesterday I got all the equipment! and ran a test with 3 cards and the 6 antenna's and IDD interference

So removed the middele card (so only top & bottem slots are occupied) and interference and heat within reasonable levels (For me).
now working on channel 2 and 10
so now I only have 4 antenna's 2x5dbi omni (channel 10) at lower level (for covering the small complex) and 2x9dbi 38cm omni (channel 2) at top level for covering users that are located at a greater distance.
test default config :
at 2 meter from station (line of sight) channel 10 -23dbi & channel 2 -19dbi
at 400m from station (station being 6meter above gnd level) channel 10 -59dbi & channel 2 -55dbi
and I have to read more about the harware configuration on MikroTik !

But was reading and learning the programing basics with the free version of ROS (Thanx mikroTik) took me about 14 days but now i know the basics only thing now to learn is how to configure pppoe and hotspot to use the same card (bridge maybe?)
The Hotspot (with pppoe) needs to be online at 12 jan 2012 so there is still plenty to learn (modify, test, etc)
Greets Jasper
Ps. Will be posting my config soon in a new post (all comments will be welcome!)