Sounds like it would be vastly cheaper to simply reflag the boat! IMHO both EPIRB and liferaft are a bit silly if you're only sailing down the coast from Croatia and plan to continue cruising Greek waters. You're never far from land nor out of VHF range, the waters are warm and there are so many boats around you're likely to have several standing by and livestreaming on YouTube while you're getting rescued.
So you'd only be buying raft and EPIRB to satisfy rules, therefore buy the cheapest ones you can find. Used ones can be often found for free, because the cost of servicing is almost the same as a new raft.
Servicing costs are considerable (several hundred EUR) and most rafts need to be serviced either every year or every 3 years. If buying new, make sure you get a 3 year service cycle one. The service cycle may drop down to annually later in the life of the raft though. Occasionally the gas bottle needs replacing, which adds another couple hundred EUR to the service fee.
Likewise, EPIRBs need to be registered and have their batteries changed regularly - look up the cost for battery changes and calculate total cost of ownership instead of just purchase price.
The situation is very different if you're planning to do an Atlantic crossing or some such. Now you would be looking at the quality of the raft instead of just the price, because there's a very slim chance you might end up sitting in it. You'd want one with a double floor (insulation against cold waters - irrelevant when summer cruising the Med), self-righting and a smaller size, as 8 person rafts with only two people inside are prone to capsize (unless you actually sail with that much crew). Viking has a good reputation. Don't buy that raft before you actually need it though.
The 24h pack is just how much food/water they stuff in there. Some sailors ask to remove the pack from the liferaft at the first servicing and carry it in a grab bag, which means it's easy to refresh/supplement the food/water and change the batteries in the flashlight.
Soft bags aren't suitable for keeping outside and few boats have on-deck lockers which would be suitable for doing so. Keeping it down the companionway is useless, as you will most likely not be able to deploy it from there in an actual emergency. Hard shells are suitable for storing on deck, or preferably in a cage overhanging the transom, from where they can be deployed by simply cutting the holding straps, so nobody needs to try and haul the massive thing around on deck with one hand in hazardous conditions, because that can only go wrong.
