I would certainly follow Hucksters advice and speak to a proefessional about thisn type of thing but be aware of what you may be offered.
Some policies may combine the policies into one cover meaning that you could claim once between you and then that is the end of the policy. Some may write seperate policies but still combine the benefit meaning that you have indeopendant policies but if you claim on the critical illness then the policy is finished. This type of policy is fine if the policy is only to cover a mrotgage. If it is more for personal cover and with no intention of covering a mortgage or other large commitment then you may want yto keep the covers seperate in which case you may be better off with what you have.
Most providers will offer all of the covbers you want but uit will be up to you to structure them how you want. You will also find that by plaicng all the covers with one company that you will save on plan fees that each policy will have. If under one single company you will pay one plan fee to cover all policies. not much. But could save you £2 - £3 per cover type per month.
When considering the options the adviser gives to you DO NOT SHOP ON PRICE. There can be so much difference between different plan types that look as if they offer the same cover. Make sure you fully understand what each policy will offer and what cover will be left in place if you make as claim. If in doubt, go to two or three advisers.