If the boots are comfortable stick with them. Boots are fiendishly tricky. Technology has little to do with it.
Skis have made some progress in that they are a little lighter, stronger and also more "carving" designed (i.e. turning is easier). Might be worth leaving the old skis at home and renting when you get there. Depends on how you feel about your skis - if they worked well and you don't mind carraige, take them!
£27 each way on easyjet but that includes your boots that would otherwise take part of your 20kg allowance. Carvers are still used and while top of the range skis might have moved on, depending on your resort, I'm sure people won't be pointing and laughing!
I did kick myself this year hiring poles for 11 for 4 days having left my 15 ones from Decathlon at home so do look into the hiring costs first.
Just do you know, Neon all in ones are tipped as the must have outerwear for next year so perhaps save your money for that!!
Boots should be good as mentioned! Having got through three sets of rental boots before buying my own with a custom liner this last holiday, knowing boots fit makes a huge difference.
You can take them as hand luggage on Easyjet (just did it a few hours ago, coincidentally!) either in the bootbag (so that's all your handluggage allowance) or cram them into a "hand luggage"-sized suitcase along with your other luggage and wear as much as you can. Or alternatively just stick them in hold luggage if you have to have hold luggage but be aware of the weight. There is no weight restriction on hand luggage but there's 20kg on hold luggage.
Bit of an old thread but I thought I'd add my twopennyworth.
My boots were 13 this year and I used them for the first time in 6 years. I tried them on and fiddled with the adjustments before I went, and found them agonisingly uncomfortable. Then, on the slopes, they worked like a dream and I couldn't even feel them while actually skiing (and it all comes straight back, much to my relief).
I've never bought skis though; too much hassle with storage and travel, especially these days. This means I get to hire new, modern ones every trip - and fitting skis takes a couple of minutes while you can be there for ages with boots.