The In Car Safety Centre had a deal on the Besafe one recently and they are worth going to and offer remote after sales support. Also, have a look on Besafe's website and see if they have any stockist near you - some of the independent ERF specialists are appointment-only and don't have premises as such, but if they stock besafe it's fairly likely they would stock Joie too so you can compare.
You might want to look at tethered seats too like Besafe Stretch? If you're concerned with safety then rear facing for as long as possible is basically the best thing you can do, and this one lasts until 125cm rather than the spin ones lasting until 105cm.
In terms of the safety rating you'll see a difference between seats which are 360 degree ie can be rear facing and forward facing (Joie 360 Spin, Joie i-Spin, Besafe izi Turn) and the ones which are 180 spin ie can only rear face and spin to the side (Joie Spin Safe, Besafe izi Twist). That's because when you have a seat with several modes they take an average of the score from each mode, and forward facing seats don't do as well in crash testing as rear facing. In terms of the Swedish Plus Test, companies only usually enter the rear-facing only version of the seat because the forward facing mode would not pass. So you'll see that Joie i-Spin Safe and Besafe izi Twist are Plus tested, but Joie Spin 360 or i-Spin 360 and Besafe izi Turn are not Plus tested.
I understand that the Besafe izi Turn & Twist are identical except for the ability to lock into forward facing or not, whereas the Joie 360 Spin / Spin Safe and the i-Spin 360 / i-Spin Safe are not quite identical, they had to add an extra bump to the top of the headrest to get the Plus Test pass on the rear facing versions.
Safety wise I'd be happy with any of them, though the original Joie 360 does have notably less side impact protection if that is a concern for you.
Lastly to note that the "B" version of the Besafe seats mean that they come with the newborn insert which you need for a baby under about 6 months. If you're moving to it after the baby seat then you don't need this, if you're looking to use it from birth, then you do.