Sharing internet with friends on a different levels. Made network with repeater Q's

[vinny809]

http://img41.imageshack.us/img41/7408/ro…
This is how my network looks like.

Now the problem is signal strength reaching the repeater. The signal stregth to the repeater is quite low - 2-3 bars. Repeater bridge gets around 4 MBps on speedtest.net in Winnie's room.
I ordered two D-Link ANT-24-0700 High gain antennas that should also help boost signal. My questions are:
1) How should I position my antennas? I currently have one antenna perpindicular to the floor and the other at a 45 degree angle(For the AP router). As shown in my drawing.

For the repeater, I have one antenna perpindicular to the floor while the other is parallel to the floor as shown.

Secondly, should I put one high gain antenna on each router or just replace both antennas on the AP router?

Any other tips on improving signal strength to my friends are also appreciated, because we are paying Premere internet service(around 15 MBps..for $70) but a lot of it is lost from weak signals.)

 

[TerryNet]

It looks like the path from the router to the repeater is going through the elevator. Should work a lot better if the repeater is positioned so that it has less obstructions in the path to the router and to the computer(s) it's servicing.

 

[vinny809]

http://img5.imageshack.us/img5/9056/network2h.jpg


Not too sure I can move my router away from elevator since there is no port in the other room where I drew the red box. Although I could buy a long ethernet cable and nail the router somewhere in that room. Currently, Nate gets 3 bars on bridge and 1 on AP. Do you think it would be better to put repeater in Nate's room? (He's on the 7th floor, almost directly above me, but on Winnie's side.)

How do you think the d-link high gain antennas would play into this?

Edit: Also, I have two WRT54GS routers on DD-WRT firmware.

On a side note, the elevator is probably affecting the signal big time. I can get 2 bars and surf the net pretty fast on the 1st floor.