No worries. You are in for a real treat with any of the e61s. One thing that I hadn't considered before is the amount of water that is used... I had decided that I didn't want a plumb-in model and the water tank is HUGE compared to my old gaggia. The reality is, with the cooling flushes and with a large americano I use about 1/3 to 1/2 the tank. This is at least twice the amount of water I have used with non-e61 machines. I'm pretty sure that I'm going to either do a plumb in conversion or some sort of external water tank solution. Search on this as well and you can see some of the clever solutions that others (on this site and on coffee geek) have employed.
General stuff...
I have used espresso machines (mostly home Gaggias and one brief period with a Starbucks Barista) for about 20 years and the Anita is a real treat! If you haven't had to tamp before or worry about grind quality you may have a steep learning curve ahead of you... I didn't ask before but I hope that you either have or are budgeting for a good grinder. Without a good grinder, any decent, non-pressurized portafilter machine will almost certainly disappoint you. Hopefully you already have one and have some tamping experience under your belt. If so, within a day or two's time, you will be pulling some of the most consistent good shots you've ever done. If you haven't, research and learn while you are waiting for the machine to arrive. Heck, even if you have, it'll give you something to do while you wait.

Also if you don't already have a good 58mm tamper, buy one before the machine gets here. Seems like all the machines come with very poor fitting, inadequate plastic tampers. This will make tamping easier, more consistent and more enjoyable. You don't have to spend a ton of money, unless you want to... Aluminum 58mm's start at around $20 and you will be sorry you didn't buy one sooner. I got by with a plastic tamper for about 18 years with my Gaggia's... If pressed, I can still pull a decent shot using the plastic one but its much harder. None of them fit properly (like about 56mm in a 58mm basket) and that causes channeling, uneven tamping around the edges *and* makes a bigger mess since when you pull it out of the portafilter there's usually coffee waiting on the rim of the tamper to fall on the counter and floor.
Please, post back what you ended up buying and your impressions of it.
Good luck,
Jim