2005 T3 aux input advice?

Hi guys,

I'm about to inherit my dad's 2005 Prius T3 (he's getting a Lexus CT) and it's the perfect car for me except for one thing: the lack of aux input. It has the non-JBL stereo with a single CD player and no nav (which i don't need as i just use Google maps). I've looked around this forum and on google and found some viable options, however none of them are available in the UK.
After searching on Amazon, i found a couple of alternatives that can be delivered in time for me to pick up the car next week:

My questions are:

1. Which one is better?
2. Will the second one work with an iPhone 6 via usb? I'm mainly concerned with steering wheel audio controls as it's quite hard to change tracks on an iPhone whilst driving. I'd (obviously) have to get a 30-pin to lightning adapter but it should work fine, right?
3. Will I need any additional cables or anything?
4. How easy are they to install? can I do it myself or am I better off taking it to Halfords and paying like £40 for them to install it?
5. Or should i just give up and get a single-din aftermarket stereo? I'm quite reluctant to do this as I'd like to keep the steering wheel audio controls and i'd rather have the storage below the stereo for my phone).
6. Back in 2005 when my dad got the Prius, he installed a Nokia Bluetooth speaker system. Would I be able to use it alongside the USB/aux input? It works fine with his iPhone 5 so it should work with my phone.

Thanks!

Edit: the Amazon links aren't showing for some reason… hope this works:

 

I really want to do that and I looked into it but I just can't afford it at the moment, hence the cheaper options. I'll look into it once I finish uni and can work full-time.
in the meantime, would an XCARLINK SKU12852 work? the website says it's not compatible with the second gen Prius but it looks the same as the one I saw on amazon except I can get this fitted without doing it myself (I don't wanna break anything)