There are really two different decisions to be made. One is how to invest the money. The other is how to «wrap» the investment. The decisions are interrelated but separate.
The investment decision depends a lot on time horizon and risk tolerance. For money you’re likely to need within 1-2 years, sadly the best option is probably to take the low interest rate in order to avoid buying an investment, losing money and then having to sell at a loss. For money you can keep socked away for 5+ years, keeping it in cash becomes a bigger risk due to inflation, and the opportunity for gains by investing becomes larger, so stocks and shares become a more relevant option. For time periods in between (money likely to be needed within 2-5 years) it is tricky: in normal times a medium term bond could be a good idea but right now by the time you’ve paid fees, you won’t end up ahead of cash unless you buy lower quality credit which means you might not get all of the principal back.
For how to «wrap» the investment there are numerous options, including from paying yourself the money and putting it into an ISA, making it a pension contribution, or perhaps keeping it within the company. Here I am no expert on what is allowed, especially re: keeping it in the company, and it may be worth getting some expert advice if you can find someone unbiased. The one opinion I would express is that I’d be nervous of maxing out pension contributions because although the upfront tax deduction is juicy, government keeps changing the rules and once money is in there, there are strict limits on getting the money out, so you could not do anything to avoid an unfavourable rule change, even if it’s bad to the point of being unfair. Meanwhile, Stocks-and-shares ISAs might be underrated, especially with talk of raising capital gains tax rates: you have to fund these with taxed money, but any gains are tax-free after that. I suppose they could also retroactively change the rules around ISA balances but there is no talk of doing that at the moment.