Some Snags

I have been working feverishly to book the travel for the trip and to arrange the accomodations and rental car. I have all the flights booked except for the one from London to Paris (I was going to take the Chunnel but it seems that flying is a cheaper option) and the rental car for the UK is arranged although not paid for. I was lucky enough to get two nights at my beautiful lighthouse (http://www.ruareidh.co.uk/), a night near Isle of Skye, a night near Loch Ness and a cute little rental car (type to be determined later).
Now for the snags...
I knew that both London and Paris were going to be expensive to stay in but I'm having a hard time figuring out the arrangements for where we're staying. I've been working on the Paris side and I don't even want to imagine the London one (although I did start that before and have a general idea of where to stay). The problem is that I read the reviews on hostelworld.com and tripadvisor.com plus any other sites that show some reviews and a lot of the places I'm looking at seem pretty dodgy. I found one outside of Paris that the metro goes to easily but it would be $650 for the 4 nights there because they don't have a 2 person room, only ones starting at 3 people and you have to pay for all 3, even if you're only having 2 stay there. The thing is that this place is getting GREAT reviews from all the sites and they say it's safe, clean and the owners are friendly (in FRANCE! Half the reviews from other hostels/hotels talk about how rude and snotty the owners/employees are). So do I pay the extra money for the peace of mind? Do I go to Expedia or Orbitz or Priceline and trust their "good" reviews (places that have received really bad reviews on sites like Trip Advisor)?
The other snag is luggage. I found the coolest suitcases on Zuca (www.zuca.com) and they also get really awesome reviews on Amazon and other sites. I ordered 2 of the sport suitcases and because I'm really bad at spatial imagery, I didn't really fathom the dimensions properly. The cute little suitcase is about the size of a banker box. That's fine for a 9 year old boy but I can't even fit my laptop in there diagonally (I should have done the math on that...it's my mistake). I had already ordered a backpack for me, one of the really big women's backpacker packs, but I'll have to use my ginormous laptop backpack to schlep my computer around. I think we'll pack Nick's daypack and use my Zuca bag as his carry on and my laptop bag as my carry on. My backpacker pack has a detachable daypack so he could use that during the daytime. We'll have a lot of time where we're driving from place to place and then, towards the end, we'll just chill in the locations. I'm thinking of getting a Pac Safe (http://www.pac-safe.com/www/index.php?_room=3&_action=detail&id=48) bag protector but that's more money out the window.
I'm already bad at saving money and budgeting and this is making it worse. Once I've figured things out, I'll post a more detailed itinerary (although is that the most wise course of action? Having it all out here on the internet...?).