I found the following one but as far as I can tell it is totally biased towards staying in the EU.
How can I get an impartial view of the effect of different deals (including Norway and Canada if possible).
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While the data given seems factually correct, I agree that the framing on that website is biased towards staying in the EU (evidenced by only giving a button to contact your MP if you're worried about leaving the EU and the non-neutral exclamation points everywhere)
As someone without a bone in this fight (As in: I'm a European, find Brexit interesting, think there are risks involved in Brexit, but there's no guarantee at all that the UK will be strictly worse off in a semi-pragmatic world) I find that TLDRNews (I'm not affiliated) tries their utter best to keep from pandering to emotions. They have outlined different possibilities for deals as given by both Brexiteers and Remainers and done their best to do both risk and benefit assessments of these possibilities.
However: Benefit assessments are simply harder to make than risk assessments. This is because current benefits and costs (as gained and paid by being a full EU member) are known and were up until recently seen as a net-gain for the UK. As such: the disappearance of these are generally categorized under 'losses'.
Possible benefits are harder to assess because these are all still hypothetical. Could the UK be better off in a few years time because they left the EU? It can, it could also be completely bankrupt, since no one currently knows the opportunities that will arise once Brexit is complete.
This unknown outcome makes the framing of Brexit as a high risk-unknown reward decision factually and objectively correct. If you don't like that, and would instead prefer a nice list of why Brexit is the holy grail of democratic decisions, you should probably check your own biases. Just like people that say that the UK will 100% be worse off should check theirs.
There's not a direct comparison of different deals on https://fullfact.org/, but a number of Brexit related questions or claims under scrutiny. Maybe that fits your search for more fact based arguments as well. To wet your appetite, here's an incomplete list of Brexit-related issues I found there: