Need advise

Hi all
I'm in need of advise, I am looking at a 1700 Storm on a 12 plate for sale but it only comes with a rider seat.
I need to get it ready for touring France with my wife but have little money left to spend after I buy the bike, I need a long haul pillion seat and sissy bar and rack (with padded back pad).
I found this on Ebay http://www.ebay.co.uk/itm/400666706041?_trksid=p2060353.m1438.l2648&ssPageName=STRK:MEBIDX:IT
but I'm a little worried the rack only takes 5Kg.
Also! as I haven't bought the bike yet and this will be my first T Bird, I'm not 100% sure what I'm buying will fit.
I am looking at spending £500ish, if it's anymore than that then I may as well go for a 1600 10 plate I'm also looking at with all the above attached.

 

I go to a few rallies each year and was concerned the rack wouldn't support our gear "tent, sleeping bag and anything else the wife think she needs"

as for spending around £500 that'll be on the pillion seat, sissy bar and luggage rack, I've seen a couple of pillion seats on ebay but not sure if I would need additional fixing brackets as I couldn't see on the ones for sale.
Also! if it's going to cost me more than £500 I may as well buy and older 1600 model with everything already on as it's only £500 dearer then the Storm

 

I'm going for the 1600, not because the storm needs those extra items but because something is a bit off with it.
Tried calling the mobile number and got a long engaged tone, then received a text from the number saying he's on holiday and can't receive calls but can text (OK! I know it can cost a bit of money to receive calls abroad) I asked him where he lives as I am over 200 miles away from my postcode but doesn't show his address, he hasn't texted me back.
I was going to do a HPI check but thought I'd go on the DVLA website and check the reg out, it came back as a Rocket III
Maybe DVLA has got it wrong but I could see no end of problems with insurance companies and maybe the police, and the asking price was surprisingly low at £5800

 

Yep!