Scotland - Wales - Ireland

I can only answer one of your questions.

"Do you know if I'll have to get a different SIM card in Ireland because it's not part of the UK?"

They are both part of the EU. This means that not only will your SIM work in both countries, but the rates for using a UK SIM in Ireland are capped, so it will not be too expensive. It will cost more than using a UK SIM in the UK, and you probably won't be able to refill a UK SIM in Ireland (unless you've been able to set up online refills and get them to work with your US credit card - apparently, only some cards work for some providers).

So, you can either top up while still in the UK and have enough for your Ireland trip, or you can just get a new SIM in Ireland when your UK one runs out. When you get your UK SIM, ask what the rates will be in Ireland, so you'll be prepared.

If you want to look at different offers before your trip, here's a list of UK providers from Prepaid GSM: http://www.prepaidgsm.net/en/uk.php. I always used to recommend their Forums, but they've been down for almost a week now. If they do come back online, they're a great place to ask for more detailed recommendations, but don't be afraid to ask for clarification, as they can get VERY technical very fast.

Three might be the one to consider - buy PAYG with the appropriate add-on for 'Feel at Home' and you would still be able to use the data when in the Republic of Ireland. Calls back into the UK (including Northern Ireland where you are spending part of the time) would also be out of the bundle and you don't pay any roaming charges if people call you. Calls to Republic of Ireland numbers would be 16.6p per minute.

One thing you may need to consider though is that in sparsely populated areas reception on any system may be patchy.

For B&B's in Scotland--and likely in Wales as well--you can use the Tourist information office to help you book a B&B. You don't have to be in the town that you are sleeping in. So, for example, you could drive to Oban from Glasgow and stop off in the Tourist office there and they can find you a place in Fort William. You can tell them what you are looking for--budget, en suite or not en suite, in town, out of town etc. I stayed in Spean Bridge when I was last in the Fort William area.

There are a lot of options in Inverness from B&B's through guest houses and small hotels to major hotels. I like staying in Inverness as you can get to some nice restaurants and here some live traditional--or nontraditional--music. Hootananny is good. Another option is to stay in one of the small towns near it. I've recently stayed on the Black Isle at The Anderson. It's been great.

Pam

Pam's suggestion works in Ireland, too. We used the T.I. office at the port on Inishmore one morning to book a room in Lisdoonvarna, our destination at the end of the day, and were really pleased with their selection and assistance.

My daughter and I spent 10 days in the Scottish Highlands/Glencoe and Skye. What a magnificent part of the world. We trained it from Edinburgh to Aberystwyth. Had to change trains in Wolverhampton with a 10 minute change over time. Guess what, we didn't make it!! Spent two hours on Wolverhampton Platform 1. Just be aware of this possibility. Loved Wales too.