Hi,

I do not know if you have thought about it but for 10 cell LiPo driven 2M F3A plane You usually have two 5 cell pack in series toget one 10 cell pack, so a charger capabale of charging 5 cell or more on two ports will work.
But You can go with two chargers also. Or one dual port charger to achive this.
If You have 110/240 volt at the flying field it may be enough with one single port charger if you get LiPo packs that can handle fast charging like 5C (current of 5 times capacity of the LiPo pack) and that way can charge rather quick each pack.
If You are going to charge from a 12 volt source like Pb (lead) supply battery (designed to handle deep discharges, not a car start battery) You perhaps would like a single charger with dual ports like ThunderPower TP820CD or Hyperion EOS 0720i Super DUO3. You need a Powersupply at home when charging at home since most chargers do not have that built in in them.
I use Hyperion EOS 0720i Super DUO3 myself and charge mostly 6 cell LiPo packs (two packs at the same time, one on each of the two charge outputs) and it works great at the field on a 80 Ah Pb marine dual purpuse (supply) 12 volt battery. I usually charge at 2C at the field. I actually bring two Pb batteries with me usually to the field if I'm going to fly all day. That is the downside when charging at the field on 12 volt source that You have to bring that with You, or have enough LiPo packs so You can fly as much You prefer and that can be expensive with 10 cell packs, I doubt that many have more then 2-3 maybe 4 such packs, the top flyers maybe have more since they probably are spnsored and can use the batteries for free. A third alternative is there also and that is to get a gas driven generator with you like the small portable one from Honda, Kipor, Yamaha.

So You have different options and many nice chargers out there for You, cheaper or more expensive that can suit different budgets.
As for 5 cell LiPo packs You have ThunderPower as one of the most expensive and HobbyKing various named LiPo on the other end of the price range.
There is 10 cell ready made packs out there also if you prefer that
Maybe You can squeeze out up to about 200 cycles out of a mid quality LiPo pack, maybe some more on higher quality, maybe less on cheaper packs.
I managed to get about 200 cycles out of my 6 cell DesirePower V8 35C 5200 mAh packs (I have 3) before they had not good enough performance for F3A flying (with my Sebart Wind S 50E plane).
Much depend of LiPo care also (like never drain it below 20% of capacity, storage charge them when not in use for example, balance charge etc).

When You tell what plane You are going to use You will get more help what motor, ESC etc that may be a good choice. If You have luck maybe someone else has converted a plane like Yours to electric and can give good advice.

/Bo