you only need 4 and 7
ph pens make me sad, but ive only used a few. keep in mind that you have alot more flexibility with a detachable probe type system. you can get cheap gell electrodes for as low as 40 bucks.
you need
wash bottle to clean the tip. buy some distilled water for this.
http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=wash+bottle
ph buffers. basic lab rules here. dont ever take measurements from these bottles. take these bottles... pour some out into a small beaker or cup.. as small as possible so as to not waste it. then take the measurements from that.. not the bottle. dont ever ever ever pour back into the origional bottle. you can get resealable nalgene bottles that are like 30ml and just wide enough to get the electrode inside them. i use these a few times then pour it out and replace it with some fresh stuff.
http://www.amazon.com/General-Hydroponics-4-01-Calibration-Solution/dp/B004HE7W42/ref=sr_1_2?ie=UTF8&qid=1347833053&sr=8-2&keywords=ph+calibration+solution
storage buffer. you may or maynot use it. ive heard that storing it in ph7 calibration buffer is just fine, but what ever you may want to look into that.
http://www.amazon.com/Hanna-Instruments-Storage-Solution-Electrodes/dp/B002NX0W2I/ref=sr_1_1?s=lawn-garden&ie=UTF8&qid=1347833200&sr=1-1&keywords=ph+storage+buffer
optional stuff.
stand... look for better deals on ebay. clamp your thing into this and simply swirle around the solution you are measuring. this will save your glass probe from accidental dropage etc.
http://www.amazon.com/MHB-LB73-SET-Laboratory-Support-Stand/dp/B002AQUJNK/ref=sr_1_cc_1?s=aps&ie=UTF8&qid=1347833266&sr=1-1-catcorr&keywords=lab+stand
cleaning solution... this is general stuff. the type you need actually depends on what contaminates your electrode. protein contaminates form milk etc require a special cleaner.
http://www.amazon.com/Hanna-Instruments-Electrode-Cleaning-Solution/product-reviews/B002NX0W4Q/ref=dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1
bottles for your buffer, however your probe is to fat, might want to find another? up to you. could look into some 100ml beakers.
http://www.amazon.com/Nalgene-2089-0001-Sample-Bottle-Narrow-Mouth/dp/B003OBYUBW/ref=pd_sbs_indust_4