There are more expensive "halal" mortgage options available and cheaper ones on the horizon.
BTW if there's no alternative available then in Islam you could mortgage a house using conventional finance.
Whether it's a good idea to buy?
It depends on your lifestyle but Imo even if you move around a lot it's still a worthwhile investment if you can find a good deal.
Everything is overpriced at the moment.
Probably be better off leaving your down payment invested jn the market until the housing market cools down.