Power consumption isnt higher or lower with different types of lighting,hps costs the same as all other types,electricity is measured & calculated by watts,a 400 watt light will use 400 watts no matter what type.
Keep in mind if electric use is a concern in say an apartment where electric is included in rent & monitered by the office there are many things you can do to balance things out so the jump in electric use wont show up.
Dig this,i know for a fact that any person can start a fresh grow using 400 watts of light & another 400 watts misc to cover pumps,cooling fans ect & have the ability to keep energy use to where the added electric used will not make a larger bill,in many cases the overall bill can go down.
Turn refrigerator & freezer down a notch,cut air conditioner use by 10%,unplug all unused devices,any device that has a standby mode or power light like a red or blue led,put those on power strips & turn power strip off when not in use,computers use alot of electricity,dont shut down computer thinking its turned off ,shut down mode still uses alot of electricity,turn all computers completely off,change all light bulbs to the next lower size than currently used,even vanity lights for grooming mirrors.
Do the things i outlined & your bill will not jump drastically & might even go down.
Ok now about the lights,if your only going to grow 2 plants than the squigely cfl lights will work perfectly,a moderator on this site who goes by the name gardengnome is also known as "seemorebuds" & is a writer/film maker,he has a book called "buds 4 less" & its exactly what you need,it shows start to finish everything a new grower needs to have a successful cfl grow.
As for how much 2 plants will smell i'll give an example,when the plants get wet they smell stronger,when plants are moved or rustled around the smell is stronger,when the plants start budding the smell greatly increases every day.
By the last 2 weeks before you harvest the smell can be as strong as a skunk spraying outside the home,how strong the smell is depends on the type,all types smell strong enough where if total secrecy is needed than carbon filters & air deodorizers should be used at all times.
Go to a website called HTG.COM which is short for high tech garden supply & look at the different complete tent packages they have that have lighting,cooling,odor control ect all included,if you cant choose a model or are not sure then call their toll free number & ask for mark,he's been there for years & knows his shit about growing,its the cheapest you will get any equipment.
Dont get too discouraged,if your going to use mj your on the best track,buying from street dealers can be dangerous & you just never know if anything toxic or even deadly is in the product,growing properly is much safer & cost effective,you can do this safely just do not cut corners on odor control or lighting as they are the most important issues.