Buying WWAN (Dell Wirless 5530) for E6400?

Hi!
I'm owner of E6400, and i'm consider now to buy Dell Wirless 5530 on ebay for 60$ include shipping (pretty cheap).

I unserstand that I can install it only if my E6400 came with preparation for it (antenna for it).

How could I check if my notebook have the extra antenna?
And if there isn't antenna installed, Can I install it? (in ebay it cost 10$)

I saw that there is place to put sim card, and there is antenna connectors for the wwan cards

I took picture, maybe it will help:

 

Sure, it looks like your system is ready. If you buy the 5530 card, it'll go right into that WWAN slot and use the 2 cables that are currently tucked away near that slot. From there, just install the software on your system and pop in the SIM card. Make sure you're buying the correct 5530 though, for your carrier.

 

I will buy unlocked and used from ebay 60$ (or 80$ for new) is cheap in my opinion..

 

Well, you can always get a better deal.

This card is unlocked and should have similar features (except it doesn't have GPS). It also costs $37 new.
http://cgi.ebay.com/ws/eBayISAPI.dl...110472402831&ff4=263602_263622#ht_6741wt_1165

 

It's fully compatible with the E6400? the only difference is GPS?

 

Are there any issues with running non-Dell WWAN cards in general? For example, if I installed a Huawei EM770W in my E4200, would the wireless switch still be able to turn it off?